This invention relates to voltage regulators and, more particularly, to a voltage regulator for regulating the supply of power by a fixed field A.C. generator which generates current to charge an electrical storage device such as a storage battery.
A voltage regulator is commonly used in an electrical system of a vehicle having a fixed field A.C. generator or alternator for charging the vehicle battery and for supplying power to system loads. The voltage regulator controls or regulates the charging of the battery by the A.C. generator in response to the battery voltage. When the battery voltage exceeds a predetermined level, which is the design or operating voltage of the battery, the voltage regulator inhibits the A.C. generator from further charging the battery, whereas when the battery voltage falls below this predetermined level, the voltage regulator enables further charging of the battery by the generator to increase the battery voltage.
One problem with prior voltage regulators is that the A.C. generator must supply all of its power all of its time of operation. When the battery voltage is below the predetermined level, the A.C. generator generates a voltage greater than the predetermined level and supplies all of its power in charging the battery and operating the system loads. When the battery voltage is at the predetermined level, the voltage regulator diverts the excess output voltage of the A.C. generator above the predetermined level to ground, and in the process the generator again supplies full power though the battery is not being charged at this time. The supply of full power by the generator during this latter time has the disadvantages of producing additional internal heating in the electrical system, continued loading of the vehicle engine, and higher fuel consumption.